Improvement in the modes of forming the air-chamber in dental-plates



" MARY ANN eou'enfroN, or NORWALK, CONNECTICUT. y

Letters Patent No. 111,429, dated January 31, 1871.

IMPROVEMENT IN'rHEMoDEs oF FoRM-ING 'rHE AIR-CHAMBER IN DE-N'rAL-PLA'rEs..

The Schedule referred to in these Letters Patent and making part of the same.

I, MARY ANN BOUGHTON, of Norwalk,' county of Fairfield, State. of Connecticut, ha ve invented au improved mode of forming the Air-Chamber in Plates for Artificial Teeth, of which the following is a specication.

- Nature mul Object of the Invention.

My' invention consists of a mode (too ful-ly explainedv hereafter to need preliminary description) of forming the air-chamber in plates for articial teeth by the use of a small block of wax or equivalent material, which is caused to adhere to the roof of the mouth while the east of the latter is being taken.

Description of theAcconqJang/'iag Drawing. Figure 1 is a perspectiveview of the instrument commonly used by dentists for holding a mass of plaster of Paris within the mouth while the impression of the upper portion of the latter is beingitaken;

Figure 2, the same, filled with a mass of 'soft plaster of Paris Eigure 3, a perspective view of a small block of wax or other material used in carrying out my invention;

Figure 4, a sectional view, illustrating the method of taking thc cast in accordance with myinvention;

Figure 5, a sectional view,o f the plaster-cast and die `forrnedon the same and Figure 6, a sectional view of the die, and mouthplate t-o which the teeth are Ato be secured.

General Description.

Artificial teeth vare ,commonly secured to metal or' hard-rubber plates, by which they are retained in their proper positions.

The plate for au upper set of teeth is fitted against the roof of the mouth, and firmly attached thereto by means of a chamber or concavity formed on the upper side of the plate, and from which the air is exhausted in adjusting the said plate to its place.

1t is necessary that the plate' should be of the same shape as and fit accurately to the roof of the mouth, in order that it may be attached to the' same, as above described.

To obtain such an accurately-fitting plate, it is usual to take an impression or cast of the interior of' the upper portion of the mouth'in plaster of Paris, ainass of the latter, suitably prepared, being placed in the concave portion@ of the holder or instrument similar v to that shown in the drawing, and then introduced into and held against the upper portion of the mouth until it sets or hardeus. n

From this cast a metal die, x, g. 5, is taken, and

the mouth-plate Y is swaged or otherwise formed on this die, as shown in iig. 6; or, where a hard-rubber plate is required, a suitable mold, instead of a die, is' formed from the plaster-cast. -4

The air-chamber I) in theplatc' has been generally formed by cutting a recess inthe plaster-cast, at what is judged the proper point, so that a correspondingprojection might be formed on the die or mold X, and consequently a recess similarto that of the cast, in the plate.

The same effect has also been produced without rccessing the cast, by securing a small block or plate to the die or mold in such a vposition that a corresponding recess would be formed in vthe plate at about the propel' point. i

The objections to the above methodsl of forming the air-chamber are, the extra amount of work required, and the fact that it is a matter of extreme difiiculty to place the air-chamber at the exact point which will best suit the wearer of the teeth aud plate, and enable the latter to be held in its place .with .the least degree of eiiort.- v

I have overcome these objections by the use of a hlock,c, of wax or other material of the size and shape ofthe required air-chamber.

This block is caused to adhere to the roof of the mouth at the exact point where itis desired to have ,the' air-chamber in the plate, after which the cast of the mouth is taken inthe usual manner, the plaster receiving the impression of the block of wax as well as of t-he roof of the mouth, as shown in fig. 4.

The succeeding operations c f forming the plate with its air-chamber from the plaster-cast thus recessed, are precisely the same as before described in connection with the usual process.

I prefer to cut or stampjthe blocks from sheet wax f of proper thickness, coated upon one or bot-h sides with glue, white of egg, and gum-Arabic; vbut it should be understood that I do not confine myself to the use of wax only, as any'other adhesive material might be used for theA purpose.

Cla/im.

The mode, substantially as herein described, of forn1'-.

witnesses.

MARY A. BOUGHTON.

Witnesses WM. A. STEEL, F. B. RICHARDS. 

